Hi, I have been looking every where for information about medicating my community tank for parasites, new additions to my tank brought lovely parasites & I must medicate asap.....I know I must remove my shrimp,crayfish,snails & clams in order to do this....My big problem is, How long must I wait to return them to the tank?? Meds box says "medicate,repeat 48 hours later if needed then do a 25% w/c. Well, I know that 25% isn't enough water to remove the medication thats harmful to my crustaceans etc.. Do you have any idea how long I should wait? or what percentage of water removal will make my tank safe again?? I really don't want to harm any of them. Thank you. C~F

You're right, a 25% water change isn't enough. Most medications can be removed by running a lot of fresh activated carbon through your filter for at least a few hours. Also, I suggest a 50% water change before that. After you're done whatever treatment regime you want to follow, do a 50% water change and add a big bag of carbon (filter bag or pantyhose) right into the filter (more than comes in those cartridges although a new one of those would help too). Run the filter and also use heavy aeration (add an extra air stone). Wait a day. Add your fish back and cross your fingers that the poison is gone enough to not matter. After a day, you could also put in a new bag of fresh carbon and run it another day to be extra sure. You're probably using a copper medication which is highly toxic to shrimp, clams, crayfish, etc. For that reason, I try to use alternative medications when needed. Good luck!